Abstract : This report considers the design and experimental results of optical detection by a cross-field multiplier image dissector photodetector. This detector is compared with the scannable traveling-wave photodetector developed previously and found to have greater sensitivity. Practical problems such as the nonuniformity of the magnetic field in the multiplier section and unusually low output coupler impedance are discussed and possible solutions presented. Further discussed are the resolution limitations as a function of the photoelectron initial velocity spread and the practical limitation in resolution determined. Experimental results of the target acquisition and tracking system employing a vidicon as the acquisition device, are discussed. This includes the maximum deflection current necessary to focus the image dissector from one edge of the photocathode to the other. The minimum discernable signal based on the present tube capabilities is determined for both direct and optical heterodyne detection. (Author)